vincent d warmerdam

Closing due to radio silence.

You're suggesting something sensible here, but part of me is a little anxious about introducing a breaking change without adding a useful feature. I think this feature is in production...

@MBrouns fair enough! We're at version `0.6.6` now, so we might want to change the behavior in `0.9.x`?

Having something that can pick up a datetime object sure sounds pratical to me. A lot of folks mentioned they were at times confused by the RadialBasis trick. Just so...

Clear. But then I have one other question; is there a reason to create both the sine and cosine columns? Why both? Also, got an exact use-case for this? One...

Let us consider the example from the [docs](https://scikit-lego.readthedocs.io/en/latest/preprocessing.html#Example).  When you use your tool to generate features for such a dataset. Does it really help a model? I'm wondering if...

@MBrouns that was indeed the direction I was thinking of. Doing that seems very sensible and I'd certainly welcome a PR with that feature.

There seems to be a bit of radio silence. @tbezemer are you still interested in implementing this?

> Is this what you meant? @tbezemer who are you referring to here @MBrouns or myself?

I think I'm cool with having a transformer for periodicity but before you start the PR we can save a lot of review time if we can discuss the signatures...